1. Field of the Invention
The present invention relates to a fuel cell that includes a fuel cell stack in which multiple fuel cell units are stacked on one another and electrochemically generates electricity using reaction gas. In particular, the present invention relates to a structure that fastens the fuel cell stack of the fuel cell.
2. Description of the Related Art
To fasten a fuel cell stack of a fuel cell, the fuel cell sometimes includes a pair of end plates respectively contact both ends of the fuel cell stack in a stacking direction of the fuel cell stack, side plates that extend in the stacking direction and disposed between the pair of end plates, and connecting bolts that connect the end plates and side members. Japanese Patent Application Publication No. 2004-185845 (JP-A-2004-185845) and Japanese Patent Application Publication No, 2006-302900 (JP-A-2006-302900) describe fuel cells in which end plates are connected to side members by connecting bolts.
As shown in FIG. 15, in a case where the end plate 61r is connected to the side member 62r by the connecting bolt 64r extending in the stacking direction, if the side member 62r is bent in a direction intersecting the stacking direction, the side member 62r operates as a nail puller that applies leverage to the connecting bolt 64r about the fulcrum Ps, and the stress is concentrated on the portion Pb of the connecting bolt 64r in the vicinity of where the end plate 61r contacts the side member 62r. Accordingly, to secure sufficient strength, the size of the connecting bolt used in such a fastening structure needs to be sufficiently large. As a result, the size of the fuel cell increases.